Mercury and selenium distribution in a defined area and in its population

In the Amiata Mountain area of Tuscany, Italy, a survey has examined the concentrations of mercury and selenium in the environment, in the food chain, and in human biological samples of blood, urine, and hair. This area was selected for study because of its large mineral deposits and concentration of elements, e.g., iron, copper, silver, antimony, and particularly mercury. Subjects consisted of a group with high occupational exposure to mercury vapor, a group randomly exposed to mercury dust, and a group nonoccupationally exposed to mercury. The selenium and mercury contents in all samples were determined by nondestructive neutron activation analysis, and results showed that the human metabolism of mercury is different from that of selenium and that the selenium retention in man could be influenced by the mercury intake. Furthermore, a great part of selenium introduced through the diet passes into the blood, where it is mainly associated with blood cells.